Slag-furnace.



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PATENTED JULY 18, 1905.

GARRETSON.

SLAG FURNAGE. l APPLICATION FILED MAR. 14, 1902. RENEWED DEU. 2. 1904.

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No. 795,032i PATBNTBD JULY 1a, 1905.

o. s. GARRBTSON.

SLAG FURNACE. APPLIoATloN Hum MAR.14,1902. Rmmwnn Dm. 2. 1904.

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UNITED STATES Patented July 18, 1905.

PATENT OEEICE.

OLIVER S. GARRETSON, OF BUFFALO, NEV YORK, ASSIGNOR TO GAR- RETSON FURNAOE'OOMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF WEST VIRGINIA.

SLAG-FURNACE.

SPECIFICATION forming part of Letters Patent No. 795,032, dated July 18, 1905.

Application filed March 14, 1902. Renewed December 2, 1904. Serial No. 235,199.

T0 all whom, t 71mg/ concern:

Beit known that I, OLIVER S. GAERE'rsoN, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York,

have invented new and useful Improvements in Slag-Furnaces, of which the following is a specification.

This invention relates to that class of slag furnaces or heaters in which the heat contained in molten slag discharged from a metallurgical furnace is utilized by heating air which is used for heating a steam-boiler or other apparatus.

The object of this invention is to produce a simple, efiicient, and desirable furnace or heater of this kind.

In my improved heater or furnace the liquid slag is first partially cooled by suitable means to the point at whichthe slag assumes asolid and non-adhesive form, and this cooling is effected in such manner that the slag has the form of comparatively thin or small sheets, pieces, or fragments. These sheets, pieces, or fragments of slag still contain the bulk of the heat andare piled in a suitable chamber, pit, or receptacle and form therein a hot mass or body which is so foraminous, loose, or porous that air can be readily blown or drawn through the same. .The air absorbs heat from the hot slag and is utilized, preferably, for heating a steam-boiler. The cooled slag is discharged from the bottom of the mass or body and fresh hot slag is supplied at the top thereof, as may be necessary to maintain the desired temperature.

In the accompanying drawings,consisting of two sheets, Figure 1 is a longitudinal sectional elevation through an apparatus embodying the invention on line 11, Fig. 3. Fig. 2 is a top plan view on a reduced scale. Fig. 3 is a transverse sectional elevation through the apparatus on the line 3 3, Fig. 1. Fig. t is an elevation of one end of the slag-congealing apparatus. Fig. 5 is a longitudinal vertical section through the congealing apparatus on the line 5 5, Fig. 4. Fig. 6 is an elevation of the other end of the congealing apparatus. Fig. 7 is a vertical section through the adjusting Like letters of reference refer to like parts I in the several figures.

The slag-congealing apparatus shown in this application consists of rolls, between which the molten slag is rolled out into a sheet or film which is delivered into the slagchamber and piled in the same.

A represents the slag-congealing rolls, which are arranged horizontally in two upright opposing sets or rows. The molten slag is delivered by a spout b to the uppermost pair of rolls and is partially cooled in passing down between the rolls and rolled out into a sheet or film of greater or less thickness and length, the size, form, and character of the sheet or film depending somewhat upon the character of the slag as to tenacity or brittleness. The rolls are preferably arranged directly over the slag chamber or pit C, so that the sheet or film of congealed slag coming from the rolls fall directly into the chamber and piles up in the same, forming a rather loose or porous and very hot body or mass through which air can be readily blown or drawn. The sheet of congealed slag breaks up more or less in descending from the rolls, owing to the brittleness of the slag, which in creases as the slag parts with its heat.

The lower portion of the slag-chamber is preferably contracted, as shown at c', and provided with a discharge-opening c2. The mass of hot slag is supported in the chamber by any suitable means in such a way that the lowermost portion of the mass of slag, which consists of cooled slag, can be gradually removed, either continually or intermittently, as may be most desirable. A convenient device for so supporting and removing the slag consists of an endless conveyer D, arranged in a horizontal discharge-passage D', underneath the slag-chamber and operated by any suitable mechanism.

E represents a steam-boiler which is heated by the air which has passed through the slag in the chamber. This boiler is conveniently arranged above the slag-chamber and on one side thereof, the boiler being preferably arranged above the surface of the ground, the slag-chamber below the surface of the ground in the form of a pit near the boiler, and the discharge-passage, so as to open through the side of the hill in which the pit is formed and on which the boiler and the metallurgical furnace are erected.

The steam-boiler, its heating passages or iues, and the boiler setting or casing F may be of any desired construction. The boiler shown in the drawings is of the Babcock and VVilcoX type, having an upper drum E and lower inclined water-tubes E2. The boiler is preferably provided with a lire-chamber c, having suitable appliances for burning any desired fuel when necessary-for instance, a grate e for burning coal. The rear wall of the boiler-casing is provided with a smokepipe f, leading to a chimney and having a damper f', by which it can be closed. The upper end of the slag-chamber C is connected with the fire-chamber e by a flue g, which opens into the {ire-chamber above the grate and in front of the fire-bridge g. The draft passes upwardly over the fire-bridge, downwardly in rear of the latter and in front of the baffle-wall g2, and then upwardly behind the latter to an outlet g3 in one of the side walls of the casing. This outlet leads to afan G, which draws the aircurrent upwardly through the slag-chamber. The air-passages -are preferably so arranged that the air is returned by the fan to the lower portion of the slag-chamber. A convenient arrangement of passages for this purpose is shown in the drawings and consists of a return flue or passage H, which leads from the fan G down to a horizontal air-passage H, surrounding the lower portion of the slag-chamber and communicating with the latter by a suitable number of short blast passages or ports L. The air is in this manner kept in circulation within the apparatus and absorbs heat from the hot porous mass of slag in the chamber and imparts heat to the boiler.

The slag-rolls may be constructed, mounted, and operated in any suitable manner. The construction of the same shown in the drawings is as follows: The rolls A are hollow and provided with means for circulating water or some other suitable cooling Huid through the same. Each roll is provided with hollow trunnions c', which are journaled in bearings c, adjustably supported in upright side frames or plates I. Thelatter are connected by front and rear plates I l2, forming, with the side frames, a casing or housing for the rolls. rlhe front plate I2 is preferably provided with a hood j, extending over the uppermost roll, as shown in Fig. 3. connect by branch pipes Ze with water-supply pipes K, and at the other side by branch pipes t" with water-discharge pipes K. Any suitable joint may be provided between the trun- The trunnions at one end nions and the branch water-pipes to permit the rolls to rotate and maintain a water-tight joint with the branch pipes. Any othersuitable arrangement may, however, be employed for cooling the hollow rolls.

The driving mechanism for the rolls shown in the drawings, Figs. 4, 5, and 6. is as follows: L represents a driving-shaft which is provided at one end with a drive sprocketwheel Z, Fig. 4, or the like,.to which power is applied. At the opposite end the shaft is provided with a gear-pinion Z, Fig. 6, which meshes with a gear-wheel Z2, secured to the trunnion of the second roll from the top of the first vertical row of rolls, the rolls of which are arranged somewhat higher than those of the second row. This gear-wheel Z2 meshes with similar gear-wheels Z3 Z4 on the adjacent trunnions of the first and second rolls in the second vertical row, and the gearwheel Z'L meshes with a gear-wheel Z5 on the bottom roll of the first row. The gear-wheels Z3 Zl do not mesh with each other,.and thc wheels Z2 Z5 do not mesh witheach other. The opposite'trunnions of the first rolls of both vertical rows are provided with gearwheels Z Z7, respectively, which intermesh, Fig. 4, and the last two or bottom rolls of the two vertical rows are also provided at their opposite ends with gear-wheels ZS Z", which intermesh. The described arrangement of gear-wheels causes all of the rolls to rotate in the proper direction (indicated by the arrows) to feed the slag downwardly between the rolls of the two vertical rows. Any other suitable or preferred arrangement of driving medium may, however, be employed.

If preferred, mechanism may be provided for adjusting the rolls of the two vertical rows nearer to or farther from each other, so as to regulate the thickness of the sheet of slag. The drawings show for that purpose wedges m, which engage against the adjustable bearings c" of the second vertical set of rolls and which are adjusted up or down by a vertical rod a and a screw-nut n', Figs. 4, 6, and 7.

The temperature of the molten slag is lowered by the rolls suflciently to reduce the slag to a solid form, in which it is no longer adhesive, butin which it still retains a large amount of heat. The sheet of hot slag is more or less brittle and crumbles and breaks up into fragments of greater or less size as it leaves the rolls and falls down in the slag chamber or y IOO IIO

The Weight of the 'accumulated slag tends to break up the sheets or fragments of slag in the lower portion of the chamberstillfurther and causes their discharge through the opening at the bottom of the slag-chamber to the conveyer or other discharge device provided for the removal of the cooled slag.

The water, which becomes heated in passing through the rolls, can be used for feeding the boiler or for other purposes.

When starting the apparatus and until the slag reaches a suliicient height in the pit or chamber, the furnace can be operated by a iire built on the grate. While the fire is burning, the damper in the smoke-flue is open and the products o'f combustion pass i'rom the combustion-chamber through the heating-passages and out through the smoke-flue. After suiiicient slag has accumulated in the slag pit or chamber to heat the boiler the damper is closed and the lire permitted to die. The fan Ur is then started and the boiler is heated by heat derived from the hot slag.

I claim as my invention- 1. The combination oi a slag-cham ber adapted to hold a pile of loose congealed slag and having air-passages communicating with its upper and lower portions, slagcongealing rolls arranged at the upper portion of said chamber 'forreceiving the molten slag, congealing the same and delivering the congealed slag to the chamber, and means for causing air to flow through said passages and the pile of congealed slag in said chamber, substantially as set forth.

2. rlhe combination of a slag-chamber adapted to hold a pile of loose congealed slag and having air-passages communicating with its upper and lower portions, slagcongealing rolls arranged at the upper portion of said said passages and the pile of congealed slag iny said chamber, substantially as set forth.

3. The combination of a slag-chamber adapted to hold a pile oi' loose congealed slag and having air-passages communicating with its upper and lower portions, slag-congealing rolls arranged at the upper portion of said chamber for receiving the molten slag, oongealing the same and delivering the congealed slag to the chamber, means for causing the air to flow through said passages and the pile of congealed slag in said chamber, and a conveyer for removing the cooled slag from the bottom of said chamber, substantially as set forth.

4l. The combination of a steam-boiler or the like having a heating-passage, a slag-chamber adapted to hold a pile of loose congealed slag and communicating at one end With the inlet of said heating-passage, a return-passage leading from the outlet ot' said heating-passage to the opposite end of said slag-chamber, con- OLIVER S. GARRETSON. Witnesses:

J No. J. BONNER, CLAUDIA M. BENTLEY. 

